the carrier uss ronald reagan off the coast of japan may be reporting today that 20 helicopters brought aid from that ship. part of a multipronged effort, not just from the united states, but from the international community to help japan at this very troubled time. chris? >> chris: greg palkot reporting from japan. greg, thanks for that. joining us now is joe sorinsioni who is an expert on nuclear issues. japanese officials are now talking about fighting two partial meltdowns in nuclear reactors. briefly, what is going on and potentially how dangerous? >> this is an unprecedented crisis, it's extremely serious. one reactor has had half the core exposed already. this is the one they're flooding with sea water in a desperate effort to prevent it from a complete meltdown. they lost control of a second reactor next to it, a partial meltdown and there is actually a third reactor at a related site 20-kilometers away they have also lost control over. they have multiple reactor crisis at the same time. we have never had a situation like this before. >> chris: what does it mean if you have a me